he xiang wrote:

Hi, all When I use thread_group to create 400 threads , it throws a boost::thread_resource_error ? Is there a limit for the number of threads created by thread_group.create_thread() ? Thanks so much.

There is no such artificial limit on the boost side. boost::thread_resource_error is always thrown, if the corresponding OS cannot fulfill the corresponding native request, e.g. if on Windows _beginthreadex fails or if on a pthread environment pthread_create fails. The most reasonable assumption is, that your OS cannot provide these 400 threads at the point where you try to get them. Greetings from Bremen, Daniel Krügler